Line the inside of a round 20cm cake tin with foil, lightly oil the inside, and heat the oven to 180C (160C fan-assisted)/350F/gas mark 4. Scatter enough fruit over the base of the tin to cover it completely, then sprinkle over 25g of the caster sugar.

In a bowl beat together the butter, the remaining sugar and the lemon zest. Beat in the eggs one at a time, then beat in the yogurt. Stir in the semolina, sift in the flour and baking powder, and fold through.

Lightly fold up to 225g of extra fruit, if you have it, through the mixture. Spoon the batter into the prepared tin and bake for 50-60 minutes, until a skewer poked in comes out almost clean. Leave to cool in the tin for 15 minutes, then turn out on to a plate. Peel off the foil and leave until cool to serve.